Telephonic testing set



Feb. '1, 1927.

R. s. COOPER TELEPHONIC TESTING SET Filed Aug. 4, 1925 5 Sheets-Sheet jnucnroz H. 1555 001 53- W w W? Feb. 1, 1927. 1,615,974

R. s. COOPER TELEPHONIC TESTING SET Filed Aug. 4, 1923 3 Sheets-Sheet 2 Feb. 1, 1927.

R. S. COOPER TELEPHONIC TESTING SET 5 Sheets- Sheet 5 Filed Aug. 4, 1923 HI ITIHHHH IHH IHP [I l Fl l I I I ll.. Llll.

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iatented' Feb. 1, 1927.

1,615,974 PATENT OFFICE.

ROBERT SCOTT COOPER, OF CONNELLSVILLE, PENNSYLVANIA.

TELEPHONIC TESTING SET.

Application filed August 4, 1923. Serial No. 655,633.

This invention relates to an improved telephonic testing set, or what I choose to name the Saftefone. It is intended for use by repairmen or trouble hunters in connection with telephone lines and instruments.

Many power companies maintain telephone lines strung on the same towers or poles with high voltage transmission lines which are often displaced by wind, sleet,

snow and other causes, so as to brin them into proximity or actual contact wlth the telephone lines, thus causing much damage and confusion, and when an attempt made to readjust these conditions, there is great danger to the lives of the repairers and trouble hunters, especially when they are dependenton testing sets which are not sufficiently well fortified or insulated against transmission of the electric currents to their.

bodies or members while making the necessary tests.

Therefore. the main object of this invention is to provide a testing set which is absolutely safe when used with ordinary care and according to rules of operation that are suggested by the. very arrangement and construction of parts which compose the testing A further object is to provide a testing set of this character which is easily and conveniently carried by one person, and which is provided with parts which are easily attached and detached, but can not be improperly attached, provision also being made for the detached parts to be stored within the box or housing which contains the electrically connected transmitter and receiver.

A furhcr vobject is to provide'a device of 'this character which is at once a test set and a highly eiti cient telephone, having embodied in its construction the most approved elements of telephone. engineering and practice. including a high impedance bridged signal. so the repairer. constructor or trouble hunter can be called when the test set is properly attached to the telephone line, the voice transmission being entirely free from distortion.

Another object is to provide a telephonic test set which gives high efficiency in signalling over heavily loaded telephone lines, and provides for receiving signals without intertcrcin c with other sets or stations.

.-\ further object. is to provide an improved and highly or. perfectly insulated or insulating unit which includes a non-electric transline. Fig. 2 is a front view of the box or housing and its permanent adjuncts, the line connector, acoustic conductor, and carrying strap being omitted. Fig. 3 is a sectional detail, the section being taken along the line 3 -3 of Fig. 2. Fig. 4 is .a' detail sectional view, the section being taken along the line 4 4 of Fig. 3. Fig. 5 is an enlarged detail view of the rubber covered plug-connection that connects with the wire tappers and with the line-jack (Fig. 15). Fig. 6 is a view, partly in section, of the insulating plug that connects the rubber tubing of the acoustic device (Fig. 12) to the electric receiver in the housing. Fig. 7 is a view, partly in section, of the insulating plug that connects the rubber tubing of the acoustic device (Fig. 12) to the electric transmitter in thehousing. Fig. 8 is a detail of the generatorcrank and handle.

Fig. 9 is a front view, and an edge view (half in section) of the handle and index for changing the circuit from the ringing condition to the talking condition and vice versa. Fig. 10 is a longitudinal sectional view of one of the wire tappers or line tappers. Fig. -11 is a diagrammatic view of the electric circuit. Fig. 12 is a side elevation of the insulating hand unit or combined acoustic or non-electric transmitter and receiver. Fig. 13 is a detail sectional view, the section being in the line 1313 of Fig. 12. Fig. 14 is a detail sectional view. the section being in the line 14-14 of Fig. 12. Fig. 15 is a sectional de tail, the section being in line 15-15 of Fig. 2.

Referring to these drawings in detail, in which similar reference characters correspond to similar parts throughout the several views, and in which the wires W an pole P are shown merely to illustrate the application of the test set, the invention will now be described as follows A box or casing 1, is formed of wood or other electric insulating material, preferably cherry wood, except the front panel 2 which is preferably of the material known by the trade name Formica'which is of high insulating value. This panel is fitted a 'alnst an inner panel 3, and both these pane s extend from end to end and top to ottom of the chamber which contains the electric transmitter, receiver and their adjuncts or electrical connections. lVithin this chamber is contained all the electric conducting elements except the line connector or wire tapper, so that I reduce to the minimum the danger of electrically shocking the operator of the device. As a further precaution, to prevent the conducting elements in the chamber from coming into such proximlty with high tension circuits as to induce a high tension in the internal conductors, the front edges of the chambers walls and top and bottom are extended forward about an inch from the outer face of the formica panel. This panel is about 4 inch thick, and the inner panel is about inch thlck, and these panels are apertured at 4, 5, 6, 7 and S, to receive the respective elements 9, 10, 11, 12 and shaft (not shown) of the generator crank 13.

The member 9 is an insulating tube which connects with the interior of the receiver 14- (preterably of the Western Electrlc type), and also connects with the insulating tube 15 (Fig. 12) through the medium of a live rubber tube 16 and hard rubber tube 17 (Fig. 1), the latter having an enlargement or collar 18 and having a long part and a short part at opposite ends of the collar, the long end fitting into the insulating tube 16, the short end being removably fitted into the tube 9, but normally fitting so snugly therein that it will not pull out by a moderate tension'of the tube 16 when extended forward of the casing 1 for use. The same is true of the connecting tube 19 whose enlarged end fits snugly but removably over the tube 10, and whose small end fits in the live rubber tube 20, the latters. other end fitting over the insulating tube 21 (Fig. 12). The tube 10 extends inward about 1% inches from the inner panel and connects to the transmitter 22 which is preferably of the type 15L. A heavy or thick plate or block 23, of insulating material, is spaced from the panel 3 by means of an insulating member 24 which co-acts with a bolt 25 and with other means for holding this block 23 securely in position. The transmitter 22 and the inner end of the tube 10 are secured to the block 23 which has an opening through which the tube 10 and a boss of the transmitter extend. From the foregoing, it is seen that the entire train of connections from the transmitter and receiver to the tubes 15 and 21 (Fig. 12) are of insulating material, and before giving a detailed description of the hand unit of Fig. 12, let it be understood that this hand-unit is entirely of insulating material, except one small brass ring, and

therefore, and in view of the factthat the combined length of the hand unit and train of connections is about 40 inches or more when extended, thereis a wide air space between the user of the hand unit and the electrically connected transmitter and receiver; but for even greater safety from possible high tension discharges of electricity, the laminated panel or duplex panel of wood and formica (2-3) are interposed between the hand unit (Fig. 12) and the electrically connected elements of the interior of the housing.

The hand unit 26 (Figs. 1 and 12) includes the tubes 15 and 21 and the block 27 to which these tubes are permanently secured. The ends of these tubes protrude from the opposite sides of the block 27, and the shorter protrusions fit into acoustic channels which extend through a socket-block 28. The protrusions that fit into this socketblock are of different diameters, so that the one of lar er diameter can not enter the socket or channel of smaller diameter, and it is impossible to interchange or improperly insert these tubes 15 and 21. One end of the channel in wh ch the tube 21 fits has its wall screw-threaded to fit :1 1V. E. adapter ot' a mouth-piece 29. The channel in which the tube 15 fits is enlarged to receive a tubular connector 30 which also fits into the intermediate or main connecting tube 31 which has a tube 32 slidably mounted therein for rotary and longitudinal adjustment so as to change the relative positions of the mouthpiece 29 and the ear-piece or receiver 33 which is secured on one end of the adjustable tube 32. The other end of this adjustable tube is provided with an annular shoulder or enlargement which is adapted to abut against a ring or hollow cylinder 31, of brass or other material, which limits the outward movement of the tube 32, being secured in place by any appropriate means. Although I have correctly spoken of this (Fig. 12) as a unitary member, nevertheless, it is capable of being separated into its several constituent elements so it can conveniently be stored in a chamber under the chamber which contains the electric transmitter and receiver, and for this purpose, a door 35 is hinged to the bottom of the casing or housing. Since all parts of this hand set or hand unit are of hard rubber or similar material, the elements 15, 21. 30 and 32 are spring-fitted in their respective seats, so they will not permit the parts to he accidentally separated. but can be separated by sutiicient manual force. The two live rubber tubes 16 and 20, their connections 17 and 19. the tubes 15 and 27. and the block 28, also combine to form a unitary element or connection which can be separated from its adjuncts and stored in the lower chamber of the casing l, and can also be separated into its constituent clcopening 7 (Fig. 2).

sunk, that the head of its pintle that secures.

it to the disk is quite out of the way from danger of contact with external ob ects. In like manner,-theouter end of the shaft 12 (Fig. 9) is guarded by the insulating knob 36 so that no metal parts are exposed at the The member 11 (Fig. 15) is a \Y. E. #204 line jack. Its outer end terminates in an annular flange which is countersunk in the inner panel 3, and the outer panel covers this flange. The \V. E. plug 37 18 joined to' one end of a 2-wire cable whose wires separate at 39, and ternnnate in wire grippers or line tappers 40 such as shown 1n Figs. 1 and 10. The inner end of the cable 38, where the plug 37 joins it, is covered with about 6 inches of live rubber tubing 38 whose inner end covers the joint around the plug 37 and effectually insulatesit from the person who uses this rubber tubing as a handle for inserting and removing the plug.

Referring now to Fig. 10, it is seen that the wooden handle 41 is tubular and of insulating material. Its axial bore 42 ext-ends through the greater part of its length and merges with an outlet 43 which is at an angle to the axis and terminates 'in the periphery of the handle near to an electric conducting clip 44 to which the end of one of the wires of the cable 38 is soldered or brazed. One end of the handle 41 is slotted to receive the wire-clamping jaws or springs 45 and 46. also the reenforcing springs 47 and 48 A spacer 49 is between the inner ends of the springs 45 and 46, and bolts 50 extend through bores of the handle, springs and spacer, thereby holding these elements securely united. One of these bolts also extends through the clip 44 and serves as a conductor from the clip to the springs which are also conductors. It is to be understood that each branch of the cable 38 extends through the channel 42-43 of one of the handles 41, and that the current is conducted thereto, from the wire w, through the springs 45 and 46. the inner bolt 50 and the clip 44. The jaw 45 has its edges flanged, and these flanges are serratethas shown at 51. These flanges also have their edges milled to form file-teeth, and the same is true of the inner face of the spring 46; s these springs being of hardened steel, will remove oxidation from the surface of the wire and thus insure a good electric contact, it being understood that the flared ends of the springs are to permit comparatively easy engagement of the wire between their ehds,and that when the wire tapper 40 is pushed forward on the. 4 wire (when in the position shown in Fig. 10), the springs ends will separate, and the wirewill slide in between the jaws and engage with the serrations 51 and be held thereby against displacement by the weight of the wire-ta-pper and cable. Although the cable may be of any desired length, about ,35 feet is found convenient for ordinary use.

The cabinet or casing 1 is provided with a door in its back, for gaining easy access to the parts contained therein; and it may also be provided with a grip-handle (not shown) in addition to the shoulder strap from which it is shown suspended. The shoulder strap may be provided with any appropriate adjusting means (not shown).

In the interior of the upper chamber (with the transmitter 22 and receiver 14) is mounted a high-impedance signal 52 (Fig. 11) which includes two bells and a clapper common to the two. This signal is permanently connected across the terminals of the test set; that is, the terminals 53 and 54 which electrically connect with the plug-terminals of the cable 38, so this signal will be sounded by every signalling current which flows over the wires w when the test set is in circuit therewith. The signal is also in circuit with the generator 55, and the latter 'in circuit with the line tappers, so that it is possible for the operator to call and be called 190 in the same manner as with permanently installed telephones, and with an equal degree of reliability. The battery 56 is also located in the upper chamber (though it may be in the lower chamber), and supplies current for the transmitter 22 when talking. The battery may be in a specially constructed container to permit removal and replacement without trouble 01' interference with the other parts in the container or chamber. It will be seen that the battery-circuit is opened and closed by the switch 57 through the medium of an insulating connector that is operated by the line-jack 11, and is open when the line-connector or plug 37 is out of the line-jack, but is closed when the plug 37 is in the line-jack.

The switches 59 and 60 may be operatively connected or related in any appropriate way with the handle or knob 36, so that the switch 59 will be closed when the index 36 is in the signalling or calling position indicated in Fig. 2, and the switch 60 will be closed when the index is in the talking or listening position indicated in Fig. 2. The switch 59 closes and opens the generatorcircuit, and'the switch 60 opens and closes the battery-circuit. The use of the induction coil 61 will be understood by those who are familiar with the art of telephony.

ber and provided with a tubular connection with another of said openings; a second transmitter, a second receiver; acoustic tubing connecting the electrically connected receiver to the said second receiver, and the electrically connected transmitter to the second transmitter, means including headed metal fasteners extending through a panel of said chamber for securing the electrically connected transmitter and receiver in place, and a panel of high insulating value covering the heads of said fasteners, for the purpose specified.

2. The combination of a chamber includ ing an inner and an outer front panel disposed in laminated relation to one another and having openings therethrough, an electrically connected receiver in said chamber, an electrically connected transmitter in said chamber, an insulating receiver outside of thechamber, an insulating transmitter outside of the chamber, insulating acoustic tubing extending through one of said openings and fitted therein so as to close it, oneend of the tubing being connected to the electrically connected receiver while the other end is connected to the said insulating receiver, and another insulating acoustic tubing extending through and fitted in another one of said .openings and having the electrically connected transmitter connected to one end while the said insulating transmitter is connected to its other end, substantially as shown, for the purpose specified.

3. The structure defined by claim 2, and said chamber having insulating top and sides and bottom which have their forward edges extended a considerable distance beyond the outer front panel for the purpose specified.

4. The telephonic test set which includes an insulating chamber comprising a front panel of high insulating value having openings therethrough; a telephonic circuit in said chamber and comprising a receiver, a transmitter, a magneto-generator, and electric conductors therefor; the crank-shaft of said generator extending through one of said openings; a crank comprising an insulating disc and a handle thereon 'for turning the disk, said disc being secured to said crankshaft and covering the end of the latter so as to insulate the latter against contact with external objects; an insulating acoustic receiver; an insulating acoustic. tubing connecting the electrically connected receiver to the said insulating receiver while extending through and closing one of said openings; an insulating transmitter; and acoustic insulating tubing connecting the electrically connected transmitter to the said insulating transmitter while extending through and closing another of said openings, for the purpose specified.

5. They combined acoustic receiver and transmitter which comprises an insulating body provided with two acoustic tubular channels, an acoustic receiver united with an end of one of said channels and communicating with its interior, an acoustic transmitter united with an end of the other channel and communicating with its interior, means to attach the other ends of these channels in communicative relation with an electrically connected receiver and an electrically connected transmitter, respectively, and means operable to efiect an adjustment of distance and angular relation of the receiver and transmitter relative to one another.

6. The combination in an attachment for a telephone comprising an apertured chamber, substantially. as described; of two fiex iblc acoustic tubes each provided with means at one end for attaching them to the chamber in open communication with two apertures of the latter; a block having two openings therethrough and provided with means for attaching the other ends of said tubes in open communication with its openings; and a combined acoustic receiver and transmitter including a body having two tubular channels therethrough in open communication with the receiver and transmitter, respectively, the said block being provided with means for removably securing said body thereto in such relation that the said openings are in open communication with said channels.

7. The acoustic hand unit which comprises a body having two channels therethrough, a mouth-piece or transmitter secured thereto in open communication with an end of one of said channels, a tube in open communication with an end of the other of said channels and secured to said body, a second tube provided with an ear-piece or receiver at one end and havin its other end slidably mounted in the first said tube so as to provide various adjustments of the mouth-piece and ear-piece relative to one another, and means to prevent accidental removal of the second said tube from the first said tube. means being provided at the other ends of said channels for attaching tubing thereto, substantially as shown.

In testimony whereof I attix my signature.

ROBERT SCOTT COOPER. 

